中国沙漠结皮蓝藻新记录属——结席藻属(Crustifilum,Coleofasciculales)及相近属的分类讨论

CRUSTIFILUM(COLEOFASCICULALES):A NEWLY RECORDED GENUS OF DESERT CRUST CYANOBACTERIA IN CHINA AND TAXONOMIC INSIGHTS INTO RELATED GENERA

为进一步推进现代蓝藻分类系统单系化发展,研究对从宁夏沙坡头的土壤结皮样本中分离纯化得到CHAB7530和CHAB7535两株丝状蓝藻进行了研究。该藻株在形态学上与束鞘丝藻类(Coleofasciculus-like)和微鞘藻类(Microcoleus-like)的物种相似,基于16S rRNA基因的序列分析表明,CHAB7530和CHAB7535与帕斯结席藻(Crustifilum hispaliculae Moreira-Fernandes,Giraldo-Silva,D.Roush&Garcia-Pichel 2021)的序列相似性达99.7%—99.9%,系统发育分析表明它们与结席藻属(Crustifilum)聚集并形成支持度良好的进化分支。此外还补充了该物种的ITS二级结构数据。结合分子、形态学和生态学数据的多相方法分析表明CHAB7530和CHAB7535为帕斯结席藻(C.hispaliculae),该属种是中国新记录属种。文章还结合系统发育分析结果,对先前从Microcoleus steenstrupii复合体中独立出来的部分属(例Parifilum)进行了分类学的修改建议讨论。

To advance the development of a monophyletic toxonomy system for modern cyanobacteria,two strains of filamentous cyanobacteria,CHAB7530 and CHAB7535,were isolated and purified from soil crust samples in Shapo-tou Nature Ecological Reserve,Ningxia Hui Autonomous Region,China.These strains exhibited morphologically simi-larities to the Coleofasciculus-like and Microcoleus-like species.Analysis based on 16S rRNA gene sequences identi-fied CHAB7530 and CHAB7535 as belonging to Crustifilum hispaliculae Moreira-Fernandes,Giraldo-Silva,D.oush&Garcia-Pichel 2021,with 99.7%—99.9%similarity in their sequences.Phylogenetic analyses showed that they clus-tered within Crustifilum and formed a well-supported evolutionary clade.Additionally,supplementary ITS secondary structure data for this species were provided.The integration of molecular,morphological,and ecological data using a polyphasic approach indicates that CHAB7530 and CHAB7535 were C.hispaliculae,which were represent new records for China.The article also discusses taxonomic revisions and proposals for certain genera previously separated from the Microcoleus steenstrupii complex(e.g.Parifilum)based on the results of phylogenetic analyses.